I have several of these now, the first ones popped up in a greenhouse tray I was starting petunias in. Another one (shown in photo) later showed up in a pot along side a damaged hoya plant I was asked to "rescue". The roots are rather thick and go down at least as far as the plant goes above the soil, if not deeper. Always seems to grow straight. Someone may have stuck grapefruit seeds in the greenhouse tray, so at first I thought it was a grapefruit tree. But the one in the picture came from a home where no one eats or buys grapefruit. It also grows quite slowly (or maybe it just needs a bigger pot?)
I'm thinking a member of the citrus family too, but until it blooms and sets fruit it might be hard to tell which one. You probably need to repot it into a deeper pot before the roots get too tangled with the other plant and it gets much larger, in case you decide to keep it when it is identified. The seeds might have been planted by birds too, You never know where they will make their deposit
Thank you, this was helpful. Now that I think about it the other plants probably are grapefruit trees, but this one is likely a different citrus tree. The other ones have slightly narrower leaves than the one in this picture as well, but I thought it was just because they are older.
